Driving mechanism



Feb; 21, 1939. J. H. coYNE 2,147,733

DRIVING MECHANISM Filed Feb. 8; 1934 2 Sheets-Sheet l 5 a? c H INVENTOR.Job) Coyz e.

Feb. 21, 1939. J c Y K 2,147,733

DRIVING MECHANISM Filed Feb. 8, 1954 2 Sheets-Sheet 2 I INVENTOR.J'o/zrz h. Coy/76.

A TTORNEYS.

Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE 2,147,733 DRIVINGMECHANISM John H. Coyne, Highland Park, Mich, assignor to ChryslerCorporation, Detroit, Mich., a corporation of Delaware ApplicationFebruary 8, 1934, Serial No. 710,205

12 Claims.

ed, under predetermined desired conditions, to v automatically effectthe drive for the vehicle. My driving mechanism is preferably adaptedfor use in connection with a speed ratio changing transmission of anydesired type, and is adapted to establish an auxiliary driving speedratio for the l5 vehicle, such as an overdrive ratio, for example.

A further object of my invention resides in the provision of an improveddriving or speed ratio changingmechanism adapted to automaticallyrespond in its actuation to predetermined desiredconditions ofoperation. of the vehicle.

Thus, by way of example, I have provided an overdrive which isautomatically effective when the vehicle attains a predetermined speedso that, on reaching this critical speed, the over- ,25 drive becomeseffective and on falling below this critical speed the overdrive becomesineifective.

In carrying outthe aforesaid objects of my invention I have provided animproved form and arrangement of an auxiliary driving mechanism which,where an overdrive speed ratio is desired for the vehicle, is driven,when inoperative as a drive, at a speed less than that of a shaft orother part cooperating therewith and driven,

from the engine. Ordinarily, I prefer to arrange my auxiliary drivingmechanism between driving or driven shafts or other parts respectivelyresponsive in their actuation to the speed of athe engine and vehicledriving speeds, theauxiliary driving mechanism being thus driven, wheninoperative, from the-driven shaft and at a speed less than that of thedriving shaft by the amount or ratio of overdrive desired.

In order to effect the aforesaid automatic engagement and disengagementof the drive through the auxiliary driving mechanism, I have provided aclutch which will automatically connect and release the clutch controlparts of the auxiliary drive under predetermined desired conditions ofrelative speeds of the engine and vehicle, or driving and driven shafts.This automatic clutch is preferably of the type having a cage or corecarrying one or more pawls or dogs responsive to centrifugal format thedesired criticalspeed for movement of the pawls into clutchingrelationship with a cooperating companion clutch memher or shell formedwith suitable pawl engaging slots or openings, the pawl carrying'cagebeing driven with either the engine driving shaft, or the vehicle drivenshaft, and the slot carrying shell being driven with the other of theseshafts. i I

If desired, other types of clutches may be used to control the auxiliarydriving mechanism within the broader aspects of my invention.

A further object of my invention resides in the provision of what may betermed primary driv- 10 ing means in addition to said auxiliary'drivingmechanism for driving the vehicle independently thereof, and in animproved form and arrangement, said means preferably being under manualcontrol so that the drive may be established in- 15 dependently of theauxiliary drive and automatic clutch associated therewith. The primarydriving means may thus provide the normal driving medium between theengine and vehicle drive either throughout the entire speed range of the20 vehicle or up to the aforesaid critical speed at which time theautomatic clutch transfers the drive to and through the saidauxiliarydriving mechanism.

Another object of my invention resides in the 25 provision of anauxiliary driving mechanism occupying a relatively small space and beingsim-' ple in construction, quiet in operation and ca- ,pable ofmanufacture at relatively small cost. Thus, according to one aspect ofmy invention,

I haveprovided an improved form and arrangement of auxiliary drivingmechanism preferably embodying a novel arrangement of planetary gearingintermediate the power driving shaft and the driven shaft, the planetarygearing driving 35 one of the clutching-parts of the automatic clutch.

It is generally desirable to provide a relatively small amount or ratioof overdrive through the auxiliary driving mechanism and where a doubleset of planetary gears is provided in order to obtain this relativelysmall amount of overdrive, such gearing undesirablycomplicates theauxiliary mechanism, occupies a relatively large amount of space and israther expensive in production. Where a single planetary gear set isused for the auxiliary driving mechanism, it is impossible to keep thesizes of the gears small in diameter and at the same time provide therelatively small amount of overdrive ratio which is usually desirable.By reason of my invention 50 I have provided a single planetary gear setwhich at the same time provides gear ratios within wide limits withoutincreasingthe sizes of theplanetary gears undesirably. In thisconnection I have provided a set of planetary gearing comprising aplanet carrier provided with double a mission between the vehicle engineand the driven planet gear pinions, these planet gear pinions wheels, orbetween driving and driven means such providing the desired auxiliarydriving ratio which as shafts of other types of devices. may be desired.The sizes of the gears may thus The transmission B may be oiiany.suitable type be kept. relatively small thereby avoiding the obsuch asthe conventional selector type operated jections and difflcultiesexperienced with asingle in the well-known manner through v the usualplanetary gear set with the usual single planetary selector controlswhereby the various adjustments gear pinion and I have also avoided themore maybe made to the transmission in'order'to procomplicated andexpensive form of a multiple vide the speed ratios in the line of drivethrough 6 arrangement of complete planetary. gear sets. thetransmission.- I I 19 A still further object of my invention residesInasmuch as transmission B may for the most in the provision of animprovedform and arpart bebf general conventional construction andrangement of overrunning or' free wheeling clutch operation, I haveshown only a portion of the as a part of the aforesaid primary drivingmeans. gearing and controls ofthis transmission in Figs.

1.5 drive h engine, the auxiliary d primary drives to be shifted byarmJl and collar I5 associated and parts associated therewith beingarranged therewith, arm i4 being actuated by the usual so that when nsaem t f h au matic elu reverse selector control to shift the gear l3 tothe a es p ace to d e the vehicle through the right as viewedin Fig. 1,for engagement with the I m 3 driving hanism, the Overrunnl g c t usualreverse idler gear I! in order to effect a go I bly thereby rendered simy reverse drive from the normal direction of drive l v th v u in ut hand primary to the driven shaft It. The idler gear 11 is in dri nl meansbeing automatically effective When I constant mesh with the drivingreverse gear l8,

the automatic clutc re e ses 85 When of the transmission countershaftIS, the latter the vehicle speed drops below the'predetermine having 9,bearing in the casing of the trans- I critical speed. mission. Thus, byappropriate actuation of the Another bject of my inventi n memes H; theusual gear shift lever (not shown) gears l3 and B e of p v d meansresponsive to mall- I! may be engaged so as to reverse the,drive, it icontrolled menlpulatienef the said speed being understood that othermanipulations of the 13 0 changing t s ssio int the 81181131581011 gearshift lever are adapted to selectively produce 39 s ttin for reversingthe normal direction 01 other desired speed ratio changes in the normalV h le v for automatieally l king out Or direction of rotation fordriven shaft l0. rendering the said overrunning clutch ineffective, Thepower coming from the usual engine or 1 ,this ea s being P ef y inadditieh t0 the other prime mover which may be located for- E manila-11ycontrolled means for the overwardly'of transmission B, drives thetransmission 11111111118 clutch automatic clutch h as and the poweristaken" from this transmission by ay he desired in S LY pe flifinstallation I a power driving means or shaft 2| rotatable in a lH'theYObjects. of my, i vent n reside in the bearing 22,. the shaft having aportion extending p s on of an improved v n mechanism and rearwardlyintothe. driving mechanism A, this.

with such arrangement, the vehicle may over- '-1 and 2 wherein I 3represents the gear adapted 15 in the novel combination and arrangementof xt di rtion or the shaft being, provided W thereof ore particularlyhereina ter d with splines 23. The rear end of shaft'2l pilots s ri ed8nd S w in embodiment in Order to the forwardly extending end of thedriven shaft illustrate the details and principles of my inven- In as mat t In, k tion, reference being had to the accompanyin .Mydrivingmechanism A provides, among other drawings'lnwhichz 1 Fig. 1 is asectional elevational view through between the driving and driven shafts2| and II my power driving mechanism. respectively, this driving meansbeing preferably Fig. 2 is a plan view thereof, the casing being of aconstruction adapted to provide a speed ratio broken away to illustratethe Ope a Darts between the shafts of an overdriving character 4 so ofthe;mechanism. whereby driven shaft It may, under certain con- Fig. 3 isa sectional elevational view taken ditions hereinafter described,bedrlven from the through the line 3-3 of Iflg. 1. driving shaft at aspeed greater than a direct Fig. 4 is a sectional elevational view'throuh a drive between the e shafts, it being understood Por i n of heoverrunning or free wh nsthat the engine will in such instances berelaclutch, the. section being taken along thev line tively slowed downwith respect to its normal 4-! of Fig. 1. I speed of actuation for agiven speed of vehicle Fig. 5 is a sectional elevational view throughtravel; 'If desired, the mechanism A may be re the automatic clutchillustrated in the disenarranged to'provide an underdrive' instead of angagedposition, the section being taken along the overdrive, although Iprefer to arrange the gear- IIneHofIHgLI. 1 I

8- 6 i8 eb et diagrammatic view of the I preferably incorporate in mydriving mechautomatlcclutch shown in Fig. 5, the clutch being anism asapart of the primary driving means illustrated in its engaged position.I between driving shaft 2|. and driven shaft ll,

. In the drawin s, I have l ustrated my driving an overrunnlng or freewheeling clutch D best a mechani m A in p w n avspeed ratio shown inFigs. 1 and 4. This clutch may in itself han transm n B a e drivenos a tll. be of anysuitable form, the fllustration showing the latterextending r rwardly to drive the rear a conventional device in which theinner cam' wheels (not shown) of the motor car or vehicle member 24 isdriven by the splines 23 of-shai't II, in the-usual well-knownmanner-{it being underthe cam faces 25 being engaged by cylinders 26 sostood that I have elected to show my invention that by the drivingrotation of shaft 2| the high 70 in association with a'mpto'r vehicledrive, a u h sides of cam faces 25 willwedge the cylinders 20 myinvention in its broader aspects is not necesbetween cam member 24 andthe outer cylindrical laflly limited thereto- Fur hermore. my vingdriven member 21 of the over-running clutch'to mechanism may be used toadvantage at various establish a direct drive thereto. The usual otherpoints'ln the line of'general power transspacers 28 maintain thecylinderslin spaced posithings; an auxiliary driving means or mechanism.

ing for an overdrive of the driven shaft I0. (3 I such that clutch 32may be shifted rearwardly 2,147,733 tion, it being apparent thatwhenever the engine or driving shaft 2| slows down, the vehicle anddriven shaft l8 may, by reason of the clutch D overrun the drivingshaft, other conditions permitting such action as will be presentlyapparent.

The cylindrical portion 21 of the overrunning clutch D is formed with arearward extension 29 provided with an annularseries of internal teethor jaws 38 complementary to corresponding teeth 3| illustrated in Fig. 1as being engaged therewith, the teeth 3| being carried by a shiftableclutch controlling device 32 driven by the splines 33 of the drivenshaft It, the arrangement being or to the right as viewed in Fig. 1 todisengage teeth and 3| and to then engage a second series of teeth 34carried by theclutch device 32 with complementary teeth 35 formed on arearwardly extending portion of the inner cam memher 24 of the freewheeling clutch D. When clutch 32 is in its forward position asillustrated in Fig. 1, the driving shaft 2| drives the driven shaft l8through the members 24 and 21 of the overrunning clutch D, the drivepassing from cylindrical member 21 and extension 29 thereof to theclutch 32. 'When the clutch 32 is shifted rearwardly as aforesaid,driving and driven shafts 2| and I0 respectively will be connectedthrough cam member 24 and clutch 32 so as to lock out or render theoverrunning clutch D inoperative.

Referring now to my planetary gearing, I have provided a sun gear 36 fixd by a bracket 36' to the casing of the overdri e mechanism A, the shaft2| freely rotating within this sun gear. I have also provided a planetcarrier 38 which includes axially spaced portions 39 and 48 thereofconnected at circumferentially spaced intervals by the tie members 4|and in between these tie members are the planet gear, shafts 42supported by the members 39'and 48 of the planet carrier 38. Journaledon each of the shafts 42 is a planetary gear pinion 43 meshing with theafore said sun gear 36, each pinion 43 having a rearwardly extendingportion thereof formed with a second planetary gear pinion 44 meshingwith the internal gear 45. The planet gears 43 and 44 have differentdiameters or they may be said to be stepped relatively to each other.Theplanet carrier 38 is held in position by the spacer sleeve 31 whichengages the sun gear 36. This internal gear is formed as a forwardlyextending portion of the outer cylindrical member 21 of the overrunningclutch D. A clutch C, preferably of the automatic tyD' has its pawls 46driven, when the clutch is disc aged, by the portion 46 of the planetcarrier 38. The pawls are adapted to engage slots 41 of the companionclutch member or shell 48. This shell is formed as an outward extensionof the cam member 24 of the overrunning clutch D and is therefore drivenat all times from the driving shaft 2| by reason of the aforesaidsplines 23. A hearing 49 is located between the rearward extendingportions of the inner and outer members 24 and 21 respectively of theoverrunning clutch D.

The aforesaid clutch 32 is provided with an annular groove 50 engaged bya yoke 5| best shown in Fig. 2. This yoke extends laterally through anarm 53 to a hub 54 fixed to a shiftable rod 55 adapted to reciprocate inguides 56 and 51 provided by the casing of the driving mechanism A. Therod 55 is bored out to receive a spring 58 reacting against a fixedabutment 59, this spring 58 acting to normally move rod 55 forwardly orto the left, as viewed in Figs. 1 and 2, to position the partsassociated therewith as illustrated in these views.

Rod 55 is connected through an arm 60 with a second rod portion 6|thereof slidable in bearing portions 62 and 63 of the casing oftransmission B, the rod portion 6| having a laterally inwardly extendingarm 64 fixed thereto. The arm 64 is normally spaced from the shiftablereversing gear |3 but is adapted for engagement therewith dur ingmovement of this gear when the latter is positioned for engagement withthe driving reverse idler gear H for establishing the aforesaid reversedrive through the transmission. The arrangement is such that when gearI3 is shifted as aforesaid into engagementwith gear 11 for establishingthe reverse drive, arm 64 will be engaged toward the latter part of themovement of gear |3 so as to move the rod 55 rearwardly or to the rightas viewed in Figs. 1 and 2, thereby shifting the clutch 32 along thesplines 33 to disengage teeth 30, 3| and to engage teeth 34, 35 to lockout the overrunning clutch D. When the reversing gear |3' is restored,spring 58 acts to restore clutch 32 to the Fig. 1 position unless heldin its rearward por tion by the manually operated dash controllingdevice which will be hereinafter re- 32 independently of the movementthereof 'under the influence of the reverse setting of the transmission.To this end I have provided a lever 65 pivoted at 66, the lever having adownwardly extending arm 61 adapted to be actuated by suitable linkagesuch as the Bowden wire 68. 'This wire, as diagrammatically illustratedin Fig. 1, extends for convenient manipulation by the-ve hicle driver,such position being indicated by the usual dash 69 which mounts a handleor knob 18 connected to the other end of the Bowden wire 68. The handle10 is adapted for movement by the hand of the vehicle driver, thishandle being guided from its position illustrated in Fig.

1 to a position in spaced relationship from dash 69, in which extendedposition the guide portion 1| of the handle registers a notch 12 thereofwith spring pressed ball 13 carried by guide block 14. The ball 13 andthe notches engageable therewith cooperate to advise the operatorof theproper positioning of handle 18 for effecting the desired movement oflever 65. It will be noted that when handle 10 is pulled outwardly fromdash 69, lever 65 will move rod portion 6| and rod 55 against thetension of spring 58 so as to shift the clutch 32 to disengage teeth 3|and to' engage teeth 34, 35 independently of this similar clutching anddeclutching action caused by the shifting of the reverse gear |3 asaforesaid. It will be apparent that when gear I3 is shifted to engagethe reverse gear l1, such movement is also independent of movement oflever 65 under the influence of handle 10. When theclutch deviceranged'pairs of lateral extensions or pawl guides 18 and 18. Extensions18 have pawl engaging faces '11 and extensions 18 have similar bearingfaces 18. Fitting within shell 48 are a pair of the said pawls 48, eachhaving a face in slidingengagement with a face 11 of extension 18 andeach extending generally inwardly of the pawl carrying cage. Thus, eachpawl is formed with a yoke'portion 18 normally seated on an extension18, each yoke portion having a guide 88 slidable intermediate a face |8and the sides of the other pawl opposite the side thereof in engagementwith the face 11. 1

In order to normally urge the pawls inwardly 1 of the pawl cage toposition the parts as shown in Fig. 5, springs 8| are provided, eachspring acting on the head 82 of the screw bolt 83 threadedly engagingsuitable openings in extensions 18, the yoke portions 18 being alsoprovided with suitable openings so as to receive the respective bolts 88and springs 8| cooperating therewith. If desired, each pawl 48 may beprovided with a spring actuated b'all detent 84 releasably engaging arecess 88' in the pawl guide portion 88 u of the other pawl to assist inholding the pawls .in stabilized condition and to prevent'hunting priorto their release for outward clutching movement.

The shell 48 has the aforesaid plurality of circumferentially spacedpawl receiving slots or openings 41 suitably spaced so thatdiametrically arranged pairs of slots will simultaneously regis- -terwith the pawls 48 so as to receive said pawls under conditionshereinafter'more apparent.

The threaded ends of screw bolts'88 permit adiustment of the springs 8|when the heads 82 of these bolts are rotated by means of a suitable toolsuch as a screw driver. Such adjustment may be readilymade by rotatingthe parts 'as asof the screw bolt heads 82 thereby permitting theaforesaid toolto be engaged. The forward extension of the cylindricalmember 21 is also provided with an,opening 88 adapted to register with asuitable opening in the casing of the auxiliary driving mechanism sothat when all of these openings are aligned the aforesaid adjustment ofD i 8s 8| is thereby facilitated.

The engaging ends of the pawls 48 are preferably provided with canffaces81 acting on the] inner edges of slots 41 to' progressively release thepawls outwardly when the clutch shell and cage are rotatingsubstantiallytogbther at a predetermined speed. When pawls 48 move outwardly in slots41, such movement is limited by engagement' of yoke portions 18 withprojections 18, the 'yoke portions sliding on the bolts 88. Shoulders 88of,.p'awls 48 also serve to limit the outward movement of the pawls,these shoulders being adapted to engage the inner portion of shell- 48adiacent the slots 41. Inward movement of the pawls 48 under the actionof springs 8| is limited by engageme of the yoke portions 19 with-theassociated pro ections 18; In operation of the power "transmittingmechanism with the parts positioned as in Fig. 1, the engine will drivef shaft -2| and hence the driven shaft iii to drive the vehicleforwardly in direct drive so far as the driving anddriven shafts 2| andI8 respec- 7 tively are concerned. This direct drive takes these sembledso that the slots 41 will register with one shaft 2| at the speed ofshaft 2| while the pawls 48 will be rotated by planet carrier member 48at a speed less than that of the drivenshaft l8 and driving shaft 2| byreason of the reduction through the aforesaid planetary gearing. Thisplanetary gearing reduction, with the parts operating as aforesaid, isobtained by reason of the internal gear 48 rotating at the speed of thedriven shaft iii, the sun gear 38 being fixed. It will be apparent thatthe stepped or different diameter planetary gear pinions 48, 44 willoperate to drive the planet carrier 38 in the same direction as that ofdriven shaft ill but at a slower speed.

By way of illustrating one manner of operation of my automatic clutch C,this clutch is illustrated as being adapted to automatically lock out orto render the free wheeling clutch D ineffective and to simultaneouslydrive shaft ill from shaft 2| at a predetermined speed of, rotation ofshaft l8 and hence a predetermined speed of vehicle travel. When suchclutching action takes place, the shaft I8 is driven from shaft 2| asaforesaid by reason. of the planetary gearing. This drive provides anoverdriveor a higher speed of the driven shaft l8 than that of thedriving shaft 2|.

An overdrive is ordinarily desirable at only relatively high speeds ofvehicle travel and hence, by ,a suitable selection and setting of thepawl springs 8|, assisted somewhat by the detents 84, pawls may be heldinoperative against the influence of centrifugal forces acting to movethe pawls outwardly until the desired predetermined critical speed hasbeen reached. Assuming, by way of example, that such automatic overdriveis desired at approximately 50 miles per hour of 7 of shaftllicorresponding to 50 miles per hour of vehicle travel, the pawls beingrestrained from moving outwardly, until the clutch parts aresynchronized, by reason of the gear reduction which vdrives the pawls ata slower speed than that of slots 41 which are driven directly fromthedriving Owing to the difference in rotational speeds of the slots andpawls, the parts pass each other with such rapidity that the pawls donot have time to move outwardly to engage the slots and the partscontinue to slip until-the operator momentarily releases or diminishesthe power of the engine applied to shaft 2| so as to permit the shell 48to decelerate by reason of the overrunning clutch D, the shifting clutch82 being 'in the position shown in Fig. l. Indecelerating,

the shell 48 obviously very quickly drops to the speed of the pawl cage,momentarily synchronizing the pawls with a pair of diametricallyarranged slots 48. the pawls thereupon being guided out during rotationthereof by cam "faces 81 for effecting initial engagement of the pawlsin the ,slots. Once engaged, the centrifugal force acting on thepawlscarries them outwardly for fully engaging the slots of shell 48 asshown in Fig. 6 and the overdrive immediately takes piace'with the freewheeling clutch Dlocked out as aforesaid. M

As long as the engine drives the vehicle at or above the aforesaidoverdrive speed with the pawls48engagedinslots4LtheclutchCwili 2,147,733remain engaged. However, when the vehicle when the vehicle drivermomentarily releases the I usual accelerator pedal to cause the vehicleto drive the engine; this reversal'of drive permits retraction of thepawls and the power transmission is then again operating without theoverdrive and through the freewheeling clutch D. a

' When it is desired to drive the vehicle in reverse, the gear I3 is'moved. by the shifter arm l4 into engagement with the reverseidler gearII. This causes rearward movement of arm 64 to move clutch 32rearwardly, as'viewed in Fig. 1, so as to disengageteeth 30, 3| andengage teeth 34, 35to lock out the free wheel clutch D; This reversedrive thus passes from shaft 2| to cam member 24, clutch 32 and thenceto the driven shaft l0, it being understood that shaft has its rotationreversed by the reversing mechanism of the transmission D. The clutch 32may also be actuated to lock out the overrunning clutch D when theautomatic clutch C is not in its clutching action, by pulling handle orknob I0 so as to cause lever 65 to actuate the rod portion 6|, rod 55and clutch 32 independently of the aforesaid shifting movement of the,reverse gear I3.

By reason of my arrangement of clutching means32 between one of the mainshafts such as the driven shaft l0 and'the overrunning clutch members 24and 21, it will be noted that in shifting clutch 32 a momentary neutralcondition exists at which time the overrunning clutch mem-.

bers are relatively disconnected, viz., one of these members such as themember 21 is released from shaft 2| and hence from the engine, and thepawl cage from the driven shaft I, such parts may be readily reversed ifdesired so as-to drive the pawl cage directly from the engine and theslots from the vehicle driven shaft, Ill. The illustrated arrangement ispreferred in certain instances since the engine continues to drive atthe overdrive speed from the time when the pawls are engaged in the pawlslots viz. at a speed slower than in direct drive for the same vehiclespeed. With the suggested reversal of clutch parts the engine would haveto operate somewhat faster by the overdrive ratio, than the driven shaftto speed up the slot carrying member and then by slowing down the enginemomentarily to reduce the speed of the pawl cage to that of the slotcarrying member, the pawls will engage the slots. In such instance, itis therefore apparent that the engine would have to drive at a speedgreater than its speed for the overdrive setting of the pawls in orderto estabw lish the proper conditions for effecting actuationof theautomatic clutch 0. However, this condition may be readily offset byarranging the pawls to engage at a somewhat slower speed than used.

.outwardly. into clutching position.

load occasioned by the pawl movement.

While I have illustrated my invention in connection with an overdrivemechanism for motor vehicles, I desire to point out that this is but oneuseful application or use of my driving mechanism which may be used toadvantage wherever 5 clutching action between two rotatable parts isdesired, particularly where suchaction is to be: automaticallyresponsive to desired conditions of relative rotatable speeds of the twomembers to be clutched or declutched. 10

While I do not limit my invention in its broader aspects, to a clutch Cof the, automatic type or to any particular relationship of springforces and centrifugal forces acting on the-pawls of'an automatic typeof clutch, I prefer to incorporate an automatic clutch as a part of myinvention and to provide the pawls thereof in substantially balanced orfloating condition at the speed of rotation of the pawl cage whereclutching action is desired. 'Thus, I prefer to arrange the. spring rateso that at the critical speed of engagement, the centrifugal forcesacting on any pawl will be" substantially counterbalanced by the pull ofthe pawl spring so that the pawl can readily move of the outwarddisplacement of the center of gravity of any such pawl, the pawl 'ispreferably also substantially counterbalanced by the inward pull of thespring associated therewith. Centrifugalforce-is proportional-to thedistance of the center of gravity of a rotatingfmass from its. axis,and'the increase of this force due to the increase of the center ofgravity distance, is I counterbalanced by an increase of the spring Thisspring rate lsthus preferably one which balances the increaseincentrifugal force during outward pawl movement.

I do not limit my dnvention, in the broader aspects thereof, to anyparticular combination and arrangement of parts such as shown anddescribed for illustrative purposes. since 'various modifications willbe apparent within the teachings of my invention as defined in theappended claims.

What I claim is? V v 1. In a vehicle drive, a power driving shaft, adriven shaft alignedwith said drive'shaft, means for establishing adirect one-way drive between said shafts including cooperatingoverrunning clutch members adapted to be driven by said shaftsrespectively, one of said overunning'clutch members having a gear driventherewith, a clutch element, a gear train for driving said clutchelerunning clutch members, each of said overrunning clutch members beingprovided with a set of clutching teeth, shiftable clutch means driven byone of said shafts and adapted to selectively clutchingly engage saidsets of clutching teeth whereby only one of said sets of teeth areengaged by said shiftable clutch means at any time.

2. A vehicle drive according to claim 1 wherein said shiftable clutchmeans is entirely disengaged, from both of said sets of clutch teeth inmoving from engagement with one to engagement with the other of saidsets of teeth.

3. In a change speed driving mechanism, a

' drive shaft, a driven shaft, anoverrunning clutch having drivinganddriven members respectively adapted for driving connection to saidshafts u At the end 5 ed for'driving connection with one of said shaftsand a second part adapted for driving connection with one of saidoverrunning .clutch members,

saidspeed ratio driving means further including speed responsiveclutching means for establishing said drive through said gear train. in.response to overrunning action of the driven shaft, clutching meanscarried by each of said overrunning clutch members, and manuallycontrolled shiftable clutch means continuously driven by one of saidshafts and adapted to be shifted intopositions of selective clutchingconnection with said clutching means of each of said overrunning clutchmembers.

, .4.- In 'a change speed driving mechanism, a drive shaft, a drivenshaft, an overrunning clutch having driving and driven membersrespectively adapted for driving connection to said shafts whereby saiddrive shaft may transmit a-direct one-way drive to said driven shaft,means including a clutch controlled gear train for. driv ing said drivenshaft from saiddrive shaft at a speed ratio different than said directdrive, said speed ratio driving means including a part adapted fordriving connection with one of said shafts and asecond part adapted fordriving connection with one of said overrunning clutch members, saidspeed ratio driving means further including speed responsive clutchingmeans for-establishing said drive through said gear trahi in responsetooverrunning action of the driven shaft, clutching means carried byeach of said overrunning clutch members, and manually controlledshiftable clutch means continuously driven by one of said shafts andadapted to shifted into positions of selective clutching connection withsaid clutching means of each of said overrunning clutch members, saidshiftable clutch means when ,in one of its said shiftable positionsserving to drivingly connect one -of said overrunning clutch memberswith one of said shaftsto provide said one-way drive, said shiftableclutch means when moved to another of its said'shiftable positions.

" driven shaft, an overrunning clutch including driving and drivenmembers respectively adapted for driving connection to said shafts fortransmitting a one-way drive therebetween, clutch teethcontinuouslydrivingly connected to each of said members, a manually shiftable clutchdevice having .teeth adapted for selective engagement with the teeth ,ofsaid overrunning clutch members, and means for driving said clutchdevice from one of said shafts, said clutch device releasing saidengagement with the teeth of'one of said overrunning clutch membersprior to engagement with the teeth of the other of said overrunningclutch members in providing a two-way direct. drive between said shafts.

6. The combination with a driving shaft and a driven shaft, of aplanetary gearing for driving said driven shaft at a different speedthan that of the driving shaft, a clutch for establishing drivingrelation between said shafts through said gearing, means for preventingthe engagement of the members of said clutch until the speed of one ofthe clutch members has reached a predetermined point, said clutch beingso constructed that engagement will not be effected until the twomembers thereof approach substantially synchronism, and means within thecontrol of the operator and cooperating with said gearing for initiallyestablishing driving connection between one of the members of the clutchand the driven shaft.

' 7.' The combination with a driving shaft and a driven shaft, of aplanetary gearing for driving said driven shaft at a different speedthan the driving'shaft and including a ring gear and a pinion carrier,an "automatic clutch for establishing driving relation between thedriving'and driven shafts through said planetary gearing when the speedof the driven shaft reaches a pre-' clutch being drivingly connectablethrough and gearing and at the will of the operator with the drivenshaft.

. 8. The combination with a driving shaft and 'a driven shaft, of aplanetary gearing for'driving said driven shaft at a diflerent speedthan that of the driving shaft, a clutch for establishing drivingrelation between said shafts through said gearing, means for preventingthe engagement of the members of said clutch until the speed of one ofthe clutch members has reached a predetermined point, said clutch beingso constructed that engagement will not be effected until the twomembers thereof approach substantially synchronism, and means within'thecontrol of the operator and cooperating with said gearing forselectively establishing driving connection between one of the membersof-said clutch and said driven shaft or directly between said drivingand driven shafts independently of said gearing.

9. The combination with a driving shaft and a driven shaft, of aplanetary gearing for, driving said driven shaft at a different speedthan that of the driving shaft, a clutch for establishing drivingrelation between thesaid shafts through said gearing, means forpreventing said members of said clutch from moving into engagingrelation until the speed of one of said clutch members has reached apredetermined point, said clutch being I so constructed that ,engagementwill not be effected until the two members thereof approach substantialsynchronism, and means within the control of the operator andcooperating with said gearing for selectively establishing drivingconnection between one of the members of said clutch and the drivenshaft or directly betweensaid gearing. v

10. The combination with a driving shaft and a driven shaft, of agearing for establishing a drive from the driving'shaft to the drivenshaft at a diflerent speed than that of the driving shaft, a clutcharranged to automatically establish a two-way drive'between said drivingand driven Y the driving and driven shafts independently or o natficclutch through said gearing with the driven a t.

11. The combination with a driving shaft and a driven shaft, of agearing for driving said driven shaft at a different rate of speed thanthe driving shaft, a one-way clutch for driving said driven shaft fromthe driving shaft, an automatic clutch for establishing a two-way drivebetween said shafts through said gearing when the speed of the drivenshaft reaches a predetermined point, and means within the control of theoperator for establishing a'two-way drive between said shaftsindependently of said one-way clutch or of said gearing, or drivinglyconnecting one of the members of the one-way clutch and one of themembers of the automatic clutch through said gearing to the drivenshaft, whereby while the speed of the driven shaft remains below apredetermined point a one-way drive will be established between saidshafts, and when thespeed of the driven shaft reaches a predeterminedpoint a twoway drive-will be estabiishedbetween said shafts through theinstrumentality of said automatic clutch and said gearing.

12. The combination with a driving shaft, and a driven shaft, of agearing for driving said driven shaft at a difierent rate of speed thanthe driving shaft, a one-way clutch for driving said driven shaft fromthe driving shaft, an automatic clutch for establishing a-two-wav drivebetween said shafts through said, gearing when the speed of the drivenshaft reaches a predetermined point, and means within the control of theoperator for establishing a two way drive between said shaftsindependently of said one -way clutch or of said gearing or connectingone of the members of the one-way clutch. to the driven shaft, wherebywhile the speed ofthe driven shaft remains below a predetermined point aone-way drive will be established between said shafts, and when thespeed of the driven shaft reaches a predetermined point a two-way drivewill be established between said shafts through the instrumentality ofsaid automatic clutch and said'gearing.

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